[Intel-gfx] [PATCH v5] drm/i915/selftests: add basic selftests for rc6

[Chris Wilson]

Quoting Andi Shyti (2020-02-05 22:49:49)
> +int live_rc6_busy(void *arg)
> +{
> +       struct intel_gt *gt = arg;
> +       struct intel_rc6 *rc6 = &gt->rc6;
> +       struct intel_engine_cs *engine;
> +       struct igt_spinner spin;
> +       intel_wakeref_t wakeref;
> +       enum intel_engine_id id;
> +       int err;
> +
> +       if (!rc6->supported)
> +               return 0;
> +
> +       err = igt_spinner_init(&spin, gt);
> +       if (err)
> +               return err;
> +
> +       wakeref = intel_runtime_pm_get(gt->uncore->rpm);
> +       for_each_engine(engine, gt, id) {
> +               struct i915_request *rq;
> +
> +               rq = igt_spinner_create_request(&spin,
> +                                               engine->kernel_context,
> +                                               MI_NOOP);
> +               if (IS_ERR(rq)) {
> +                       err = PTR_ERR(rq);
> +                       break;
> +               }
> +
> +               i915_request_get(rq);
> +               i915_request_add(rq);
> +
> +               igt_wait_for_spinner(&spin, rq); /* it's enough waiting */
> +
> +               /* gpu is busy, we shouldn't be in rc6 */
> +               if (is_rc6_active(rc6)) {
> +                       pr_err("%s: never busy enough for having a nap\n",
> +                              engine->name);
> +                       err = -EINVAL;
> +               }
> +
> +               igt_spinner_end(&spin);
> +               if (i915_request_wait(rq, 0, HZ / 5) < 0)
> +                       err = -ETIME;
> +               i915_request_put(rq);
> +               if (err)
> +                       break;
> +
> +               intel_gt_wait_for_idle(gt, HZ / 5);
> +               intel_gt_pm_wait_for_idle(gt);
> +
> +               /* gpu is idle, we should be in rc6 */
> +               if (!is_rc6_active(rc6)) {
> +                       pr_err("%s is idle but doesn't go in rc6\n",
> +                              engine->name);
> +                       err = -EINVAL;
> +                       break;
> +               }
> +       }
> +       intel_runtime_pm_put(gt->uncore->rpm, wakeref);
> +
> +       igt_spinner_fini(&spin);
> +       return err;

I'm afraid I think we should split the patch one more time, and push
ahead with live_rc6_busy() as that should be working regardless of our
discovery process around the thresholds.
-Chris